Feed mechanism for saw-mill carriages



(No Model.) A. E. HOFFMAN.

FEED MECHANISM FOR SAW MILL GARRI AGES. No. 379,163. Patented Mar. 6, 1888.

UNITE STATES PATENT OFFICE.

ANDREW E. HOFFMAN, OF FORT WAYNE, INDIANA.

FEED MECHANISM FOR SAW-MILL CARRIAGES.

SPECIFICATION forming part of Letters Patent No. 379,163. dated March 6,1888.

Application tiled November 19, 1887. Serial No. 255,584. (No model.)

' To all whom it may concern:

Be'it known that 1, ANDREW E. HOFFMAN, of Fort \Vayne, county of Allen, and State of Indiana, have invented certain new and useful Improvements in Feed Mechanism for SawMill Carriages, of which the following is a full, clear, and exact description, that will enable others to make and use the same, reference being bad to the accompanying drawings, forming apart of this specification.

The object of this invent-ion is an improvement-on a part. of the mechanism set forth in Letters Patent No. 370,944, issued to me on October 4. 1887.

Figure l is a vertical longitudinal section of a saw-mill carriage embodying my improved features, and Fig. 2 a side elevation of the friction feed mechanism.

In the drawings, A represents the log-carriage, Aone of the track rails upon which the same moves, and B the friction propellingribbon located underneath and secured to the respective ends of said carriage, as shown in Fig. l.

The friction device for gripping the ribbon B is supported in a suitable frame, and located underneath the log carriage, as shown in Fig. 1. This particular improvement relates to the connection between the operating-lever and the rolling bodies for transmitting the required reciprocating movement to the carriage.

C C are companion friction-drums,mounted on shafts O 0 which have suitable journalbearings in the horizontal part of the frame or casting B as shown. These drums are placed below and in the pathway of the traction-rib-' bon B, and have an intermittent frictional contact with the same. Any suitable means may be employed for transmitting the required motion from the motive power to the shafts C 0 the drums revolving in opposite directions relative to each other, as indicated by the arrows.

Above the ribbon B, and in line with the friction driving drums O O,are located the adjustable friction gri pping-rollers D D, mounted on the shafts the, the ends of whichare in turn plates or arms bb b"b. The outer ends of these arms are pivoted to the top part of the,

standards b b The upper ends of the four vertical connecting-rods D D are pivoted to the inner adjacent ends of the armsb b b b, thetwo rods D being on the front side, and the two companion rods D at the back side. In this case these rods are in two parts, the joining ends having a right and left handed screw-thread, and being connected by means of the adjusting sleeve or sleeves If, correspondiugly screwthreaded, whereby these rods may be lengthened or shortened, as required, in order to limit the throw and maintain the proper relative position of the friction gripping-rollers. -The object of this construct-ion is to provide means whereby the least variation and wear may be compensated for and these parts all kept adjusted to a nicety. By this arrangement the rollers D D arejournaled independently of each other and therefore have an independent adjustment, which was not the case in the former patent herein referred to.

The journal-boxes for the shafts c a are also provided. both above and below, with a number of shims or liners b", which maybe changed in compensating for the wear of the rollers or drums.

The rock-shaft D is'journaled in the down Wardly-projecting part of the framework and below the friction-drums, as shown, and has the lower end of the operating-lever E rigidly mounted on the outer projecting end of the same. On this rock-shaft and inside of the frame-work is rigidly mounted the elongated rocker arm or plate d, projecting laterally from each side of said rock-shaft. The companion rods 01 d pass through and are rigidly secured in the ends of the rocker-arm d and at each side of and parallel with the rocker-shaft D. The lower ends of the verti cal connecting-rods D D are rigidly secured to the respective ends of the horizontal rods (1 d, as shown in the drawings. By this construction and arrangement it will be observed that when the operating-lever is in a true vertical position the log-carriage is at rest, as there is no pressure on the propelling-ribbon B, lying between the friction-drums and roll-- one end of the rockerarm d and raising the other, and imparting a corresponding movement to the inner ends of the rocker-arms I) 0, through the medium of the horizontal rods (M and the vertical connecting-rods D D which has the effect of bringing the friction-roller D down on top of and gripping the ribbon B between the rolling bodies, and thus imparting motion to the carriage in one direction. Shifting the operating-lever to the left moves the carriage in the opposite direction. This alternate shifting of the lever causes a corresponding movement of the friction gripping rollers, and the required reciprocating movement is transmitted to the log-carriage. Practical working demonstrated the fact that it was better to have the friction-rollers journaled in separate arms than in one and the same rocker-arm, as shown in the patent herein referred to, as a more sensitive and positive adjustment could be secured and a higher speed of the carriage more easily eontrolled. This arrangementgives the same coincident action, as set forth in a former patent. and, in addition thereto, an independent adjustment, so as to conveniently take up all the lost motion and compensate for any uneven wear of the frictional bodies, thus constantly maintaining the required accuracy necessary to allow of quick handling and the complete control of the carriage.

Having thus described my invention, what I claim as new, and desire to secure by Let ters Patent, is

1. As a means for transmitting a reciprocating movement to log-carriages, the combination, with the carriage, of a traction-ribbon secured underneath to the respective ends of said carriage, the friction grippingrollers mounted on the shafts a a", the rocker plates or arms I) b b b,in which said shafts are jonrnaled, the standards I) I), supporting the outer pivoted ends of said arms, the connecting-rods D D, pivoted at their upper ends to the inner ends of said plates or arms, the rockerarm (I, the rods (7/ (1, the rock-shaft D, upon which said arm (Z is mounted, and the operating-lever secured on the end of said rockshaft, all substantially as and for the purpose set forth.

2. In a means for transmitting motion to log-carriages, the combination, with a tractionribbon properly secured to said carriage, of the friction driving-drums, located underneath and in the pathway of said ribbon and rotating in opposite directions relative to each other, the friction gripping-rollers placed above said ribbon andin line with said drums, the rocker plates or arms I) b 1/1), in which the shafts carrying the gripping-rollers are journaled, the connecting-rods D" D, constructed in two parts, the respectivejoining ends having a right and left screw-thread, the sleeve or sleeves b",correspondingly threaded and adjustably connecting said ends, the rocker-arm d, the rods (Z (Z, the rock-shaft I), and the operating-lever mounted on said shaft, substantially as and for the purpose set forth.

The combination. with the rocker-plates I) I) I) I) and the friction gripping-rollers journaled in the same, of the eonnectin 'a'ods D D, constructed in two parts and having the joining ends threaded, as described, the sleeve or sleeves I), correspondingly threaded and adjustably connecting said ends, the rockerarm (I, the rods (7, d, and the rocl -shaft D, substantially as and for the purpose set forth.

ANDREW E. HOFFMAN.

\Vi tn esses i J. R. I'IOFFMAN, E. G. SHULZn. 

